How do you solve $9 - 3 x = 21$ $9- 3x = 21$ ?

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Answer 1 · 2017-05-16T21:51:53

See a solution process below:

First, subtract $9$ $color(red)(9)$ from each side of the equation to isolate the $x$ $x$ term while keeping the equation balanced:

$- 9 + 9 - 3 x = - 9 + 21$ $-color(red)(9) + 9 - 3x = -color(red)(9) + 21$

$0 - 3 x = 12$ $0 - 3x = 12$

$- 3 x = 12$ $-3x = 12$

Now, divide each side of the equation by $- 3$ $color(red)(-3)$ to solve for $x$ $x$ while keeping the equation balanced:

$\frac{- 3 x}{- 3} = \frac{12}{- 3}$ $(-3x)/color(red)(-3) = 12/color(red)(-3)$

$(color(red)(cancel(color(black)(-3)))x)/cancel(color(red)(-3)) = -4$

$x = -4$

How do you solve 9- 3x = 219−3x=219- 3x = 21?